1. Field of the Invention
The present invention relates to a lane lens sheet using a light transmission rate difference, and more particularly, to a plane lens sheet using a light transmission rate difference, which is used for stereoscopic printing for a lenticular system and an integral photography method and has a plane surface while innumerable lenses are arranged on the surface thereof so that it looks like a flat transparent sheet, improves the quality of stereoscopic products employing the lens sheet and facilitates the maintenance of the stereoscopic products.
2. Background of the Related Art
Generally, a stereo lens sheet includes innumerable lenses formed in a pattern on its surface so that the surface looks embossed. The lenses of the stereo lens sheet are used to obtain refractive effect. However, the surface of the stereo lens sheet is embossed because of the lenses formed thereon, and thus there are many problems in manufacturing products employing the stereo lens sheet and managing the products. That is, particles collect between embossed portions on the surface of the lens sheet and they are difficult to remove by cleaning. Accordingly, the transparency of the lens sheet is deteriorated so that the life span of the lens sheet is shortened.
Furthermore, the embossed surface of the lens sheet causes diffused reflection so that products employing the lens sheet look lusterless. Thus it is difficult to produce a lustrous lens sheet.
A stereoscopic printing lens sheet has a lens pitch that determines the resolution of a three-dimensional (3D) object. The correlation of the resolution of the stereo graphic and sense of depth is obtained based on the lens pitch. When the lens pitch is increased, the interval of lenses of the lens sheet is widened, which means the lenses have a large size. Thus, the resolution of stereo graphic seems poor while the sense of depth seems improved when the stereo graphic is seen with the naked eye.
Accordingly, to improve both resolution and sense of depth, a method of increasing the radiuses of curvature of the lenses of the lens sheet was used to improve the sense of depth while narrowed the interval of the lenses. However, this method narrows a 3D object recognition angle though it improves resolution and sense of depth.